Robert gray



@uitrit tetra @anni @ffice ROBERT-GRAY, or LITGIIFIELD, ILLINOIS.

' Leners Parma N, 56,702, dared July i6, 1867,

IMPROVEMENT IN ELLIPTIG SPRINGS..

TO ALL WHOM IT MAY GONGERN:

Bc 1`t`known `that I, ROBERT GRAY, of Litchfield, in the county ofMontgomery, and State of' Illinois, have invented a new and usefulImprovement in Corrugated or RibbedSprings and I do hereby declare thatthe following is al full and clearl description thereof, reference beinghad to the accompanying drawings, and' to the letters of referencemarked thereon.

This invention consists lforming each of the leaves of a spring 1nto alongitudinal corrugation, thc said corrugations being so arranged anditted together in the different leaves as to greatly strengthen thespring, and

at the same time to increase its elasticity. The shape of thecorrugations, as represented on the faces ot the spring leaves, willben'early or quite parabolic, with convex contour at the ends of' saidcorrugations. The.

general form of the corrugations, in elevation, is such that the varyinglengths of leaves which go to 4make up the spring will fit nicelytogether, that is, a long one upon a short one, and vz'ec versa.

To enable those skilled in the art to make and use my improved spring, Iwill proceed to describe its con struction and operation. v 4

Figure l of the drawings is a side elevation of onc of the improvedsprings, the dott-ed lines showing corrugation of one leaf entering thethickness or" another.

Figure 2 is a side elevation of one leaf.

Figure 3 is a plan of one leaf.

Figure 4 is a transverse section bisecting one leaf.

This spring may beelliptical in its formation, or it may be asemi-ellipse, as is represented the spring A in the drawings. Thislatter variety is the more common for locomotives and other similarheavy purposes. The spring A is made up of a number of leaves a in thesame manner as springs now in use. In each of these leaves there is acorrugation or longitudinal rib a', projecting outwardly from' theconvex side of the leaf, and nearly its entire length: Thesecorrugations or ribs; are to be pressed or rolled out of the solid.melalof which the leaf is formedfand in such a manner as to make thewidth and projection ofthe rib much larger and stiffer ii thecentrellongitudinall'y) of the leaf than toward the ends. Thisarrangement forms the horizontal projection of the base ofthe rib,vnearly or quite in a parabolic curve, as seen clearly'ing. v3. At thcends of the ribs a', where the two parabolic curves meet, they should beconnected by an easy curve, as is also shown in Iig. 3. The ribs shouldnot extend the whole length of the leaf', but stop short of thehanger-seat of thc long elliptical curve, as shown in fig. 3, andsubstantially for the purpose set forth. v

leaves, but approach more nearly to thccnds of the shorter ones. Thelwhole con-struction should be such that the convex side of one ribvwill fit into the concave side of another.A The widening ofthe rib-inits centre gives it a corresponding increase or" depth and. consequentlyof strength at that point, and from the centre of each spring thusconstructed to its ends there isnn increasing elasticity. Springs may beconstructed in this manner much more cheaply, both as regards materialused and labor required for thcmanufncture, and the springs soconstructed will also bc'much more clasticand also more du'rahle. Aband, B, may be used, ns formerly, to connect thc different leavestogether 4into the form of a spring.

Having Vdescribed my invention, what I claim is l T Projccting a rib,a', from the convex side of a lent` of tlie'spring, so as to form arounded parabolic curve or ROBERT GRAY.

Witnesses H. C. WATSON, J'. H. FILEER.

